Camshaft lift indicator



Jan. 8, 1957 CAMSHAFT L Filed 06 H. M. SHEPPARD IFT INDICATOR Howard 'M.Sheppard INVENTOR.

United States Patent CAMSHAFI LIFT INDICATOR Howard M. Sheppard,Columbus, Ohio Application October 1, 1953, Serial No. 383,607

2 Claims. (Cl. 33-481) It is therefore a primary object of thisinvention to provide an improved tool constructed specifically for usein conjunction with automotive engines which will enable an operator todetermine the effective lift of the cam lobes of the engine withoutnecessitating removal of any other structure except the rocker arm coverplate and rocker arm assemblies. This invention is directed primarily totools for use with 1949 Cadillacs and later, although it will be readilyappreciated that the same may be designed for use with other engineshaving overhead valve construction.

These together with other objects and advantages which will becomesubsequently apparent reside in the details of construction andoperation as more fully hereinafter described and claimed, referencebeing had to the accompanying drawings forming a part hereof, whereinlike numerals refer to like parts throughout, and in which:

Figure 1 is a perspective view of the tool;

Figure 2 is a vertical section taken through the tool showing the samein mounted relation on an associated ens Figure 3 is a perspective viewof an adaptor rod used in determining the effective lift of a camshaftfuel pump lobe;

Figure 4 is a bottom plan view of the lock nut; and

Figure 5 is a perspective of a spacer plate for use in conjunction withthe tool component shown in Figure 3.

Referring now more particularly to the drawings and more specifically toFigures 1 and 2 thereof, reference numeral indicates generally anelongated plate member which forms a mounting plate for the toolassembly and which is provided adjacent one end thereof with a threadedaperture as indicated by the reference character 12 and at the oppositeend thereof with a generally V-shaped elongated aperture indicated bythe reference character 14. A sleeve member is indicated generally bythe reference character 16 and it will be noted that this member isprovided with a smooth internal bore 18 and has its outer surfacethreaded throughout its extent. The lower end of the sleeve member isthreadedly engaged within the threaded aperture 12 of the base plate anda lock nut member indicated generally by the reference character 20 isalso threaded on the lower end of the sleeve such that its lower surfacewill bind against the upper surface of the mounting plate and maintainthe proper adjustment between the sleeve member and the base plate for apurpose which will be presently apparent. The upper face of the mountingplate is provided with a depression 22 of cup-like configuration and thebottom surface of the nut member 20 is provided with an arcuate trough24, which portions receive a ball member 26 in a manner shown mostclearly in Figure 2. It will be noted that the cooperation between thedepression 22, the trough 24 and the ball member 26 is such that the nutmember 20 is eflfectively locked with relation to the sleeve and themounting plate and will prevent accidental displacement or rotation ofthe sleeve with respect to the mounting plate.

The upper end of the sleeve is split at opposite sides thereof asindicated by the reference character 28 and one side of the upper endportion is flattened as indicated by the reference character 30. Thebarrel 32 of a dial indicator indicated generally by the referencecharacter 34 is slipped into the bore at the upper end of the sleevemember and a collar member 36 surrounding its upper end is provided witha set screw member 38 having a knurled finger knob portion 40 such thatthe set screw may be engaged with the upper end of the sleeve to clampthis portion thereof into frictional engagement with the barrel 32 andprevent longitudinal displacement between the sleeve and the barrel. Theindicating or movable spindle 42 of the dial indicator terminates in aconventional enlarged head portion 44 which is disposed within the bore18, in the manner shown most clearly in Figure 2.

in utilizing the above described assembly, it will be manifest that therocker arm cover and rocker arm assemblies must be removed whereupon afastening element 46 is inserted through the elongated aperture or slot14 for engagement with one of the tapped holes which was utilized tomount the rocker arm assembly. The mounting plate is then manipulatedsuch that the conventional valve push rod 48 is guidably received withinthe bore 18 of the sleeve 16, it being noted that the cup 50 thereofengages the inner surface of this bore. It is now necessary to rotatethe crankshaft or camshaft of the engine such that the heel of the camlobe under consideration is in engagement with the valve lifterassociated with the push rod 48. At this point, the nut 20 is backed offand the sleeve 16 threaded into or out of the mounting plate 10, as thecase may be, such that the needle of the dial indicator is deflected aslight amount, at which point the locking nut 2h is manipulated to holdthe desired adjustment and the dial indicator is zeroed in aconventional manner. The engine crankshaft is then rotated until amaximum reading is obtained on the face of the dial indicator wherebythe operator may record the over-all effective lift of that associatedcamshaft lobe. This operation is, of course, repeated as many times asis necessary to check the valve mechanisms under consideration.

Referring now more particularly to Figures 3 and 5, the assemblies shownare to be utilized in conjunction with determining the effective lift ofthe fuel pump lifter lobe on the camshaft. In this respect, a spacerplate indicated generally by the reference character 52 is positionedbetween the engine block and the mounting plate 10 with the usual fuelpump mounting elements projecting through the apertures 54 disposed atopposite ends of the spacer plate which will position its enlargedaperture 56 in registry with the opening for the fuel pump push rod. Thefuel pump push rod is also removed and a calibrated dummy rod 55 isinserted in its place such that its tapered upper end portion 60 willproject into the bore 18 of the sleeve 16 when one of the fastenerelements extending through the bores 54 in the spacer plate is utilizedto fasten the mounting plate 10 on top of the spacer plate. Theoperation for determining the lift of the fuel pump cam lobe isessentially the same as that previously described in conjunction with avalve cam lobe.

From the foregoing, the construction and operation of the device will bereadily understood and further explanation is believed to beunnecessary. However, since numerous modifications and changes willreadily occur to those skilled in the art, it is not desired to limitthe invention to the exact construction shown and described, andaccordingly, all suitable modifications and equivalents may be resortedto, falling within the scope of the appended claims.

What is claimed as new is as follows:

1. A camshaft lift indicator comprising a mounting plate, said mountingplate having an elongated t -shaped slot therein for the reception of afastening element and having a threaded aperture adapted to surround aninternal combustion engine valve push rod, a sleeve member having itslower end portion engaged within said aperture such that its boreguidably receives the upper end of an associated valve push rod, and adial indicator having its barrel frictionally engaged within the upperend of said sleeve with its spindle projecting downwardly therein withthe free end of the spindle spaced from the lower end of the sleeve forabutting the upper surface of the associated push rod, whereby rotationof the engine crankshaft will effect a reading on the dial indicatorindicative of the total lift of the cam lobe under consideration.

2. In combination with an overhead valve internal combustion engineincluding a cylinder head having valve push rods extending therethrough,a camshaft lift indicator comprising a mounting plate having an apertureadjacent one end and an elongated V-shaped slot adjacent its other end,a fastening element extending through said slot and securing saidmounting plate to said cylinder head with the aperture thereofsurrounding one of said push rods, an upstanding sleeve member havingits lower end portion received in said aperture such that its boreguidably receives the upper end of the associated push rod and a dialindicator having its barrel frictionally engaged within the upper end ofsaid sleeve with its spindle projecting downwardly therein with the freeend of the spindle spaced from the lower end of the sleeve for abuttingthe upper surface of the associated push rod, whereby rotation of theengine crankshaft will effect a reading on the dial indicator indicativeof the total lift of the cam lobe under consideration.

References Cited in the file of this patent UNITED STATES PATENTS789,499 Lightholder May 9, 1905 1,154,704 Leyson Sept. 28, 19151,160,630 MacKinnon Nov. 16, 1915 1,758,271 Zitzman May 13, 19302,104,234 Linne Jan. 4, 1938 2,105,502 Pointer Jan. 18, 1938 2,642,670Dow June 23, 1953

